<template>
    <div id="tags-view-container" class="tags-view-container">
        <scroll-pane ref="scrollPane" class="tags-view-wrapper" @scroll="handleScroll">
            <router-link
                v-for="tag in tags"
                ref="tag"
                :key="tag.path"
                :class="isActive(tag)?'active':''"
                :to="{ path: tag.path }"
                tag="span"
                class="tags-view-item"
                :style="activeStyle(tag)"
                @contextmenu.prevent.native="openMenu(tag,$event)"
            >
                <span @click="changeTag(tag.path)">{{ tag.name }}</span>
                <span v-if="!isAffix(tag)" class="el-icon-close" @click.prevent.stop="closeTag(tag)"/>
            </router-link>
        </scroll-pane>
        <ul v-show="visible" :style="{left:left+'px',top:top+'px'}" class="contextmenu" @mouseleave="closeMenu">
            <li v-if="!isAffix(selectedTag)" @click="closeTag(selectedTag)">
                <i class="el-icon-close"></i> 关闭当前
            </li>
            <li @click="closeOthersTags"><i class="el-icon-circle-close"></i> 关闭其他</li>
            <li v-if="!isFirstView()" @click="closeLeftTags"><i class="el-icon-back"></i> 关闭左侧</li>
            <li v-if="!isLastView()" @click="closeRightTags"><i class="el-icon-right"></i> 关闭右侧</li>
            <li @click="closeAllTags"><i class="el-icon-circle-close"></i> 全部关闭</li>
        </ul>
    </div>
</template>

<script>
import ScrollPane from './ScrollPane'
import {mapState, mapMutations} from 'vuex'

export default {
    components: {ScrollPane},
    data() {
        return {
            visible: false,
            top: 0,
            left: 0,
            selectedTag: {},
            affixTags: []
        }
    },
    computed: {
        ...mapState(['tags']),
    },
    methods: {
        ...mapMutations(['closeTagOp', 'closeOthersTagsOp', 'closeAllTagsOp', 'closeLeftTagsOp', 'closeRightTagsOp']),
        isActive(tag) {
            return this.$route.path === tag.path;
        },
        activeStyle(tag) {
            if (!this.isActive(tag)) {
                return {};
            } else {
                return {
                    "background-color": '#409EFF',
                    "border-color": '#409EFF'
                }
            }
        },
        isAffix(tag) {
            return this.tags.indexOf(tag) === 0
        },
        isFirstView() {
            return this.tags.indexOf(this.selectedTag) <= 1
        },
        isLastView() {
            return this.tags.indexOf(this.selectedTag) === this.tags.length - 1 && this.tags.indexOf(this.selectedTag) !== 0
        },
        changeTag(path) {
            this.$emit('changeTag', path)
        },
        closeTag(tag) {
            let index = this.tags.indexOf(tag)
            if (index === this.tags.length - 1) {// 最后一个
                this.changeRoute(this.tags[index - 1])
            } else {
                this.changeRoute(this.tags[index + 1])
            }
            this.closeTagOp(tag);
        },
        // 关闭其他tag
        closeOthersTags() {
            let tag = this.selectedTag
            this.changeRoute(tag)
            this.closeOthersTagsOp(tag)
        },
        // 关闭左侧
        closeLeftTags() {
            let tag = this.selectedTag
            this.changeRoute(tag)
            this.closeLeftTagsOp(tag)
        },
        // 关闭右侧
        closeRightTags() {
            let tag = this.selectedTag
            this.changeRoute(tag)
            this.closeRightTagsOp(tag)
        },
        closeAllTags() {
            if (this.$route.path !== '/index') {
                this.$router.push('/')
            }
            this.closeAllTagsOp()
            this.closeMenu()
        },
        changeRoute(tag) {
            if (!this.isActive(tag)) {
                this.$router.push(tag.path)
                this.$emit('changeTag', tag.path)
            }
            this.closeMenu()
        },
        // 打开右键菜单
        openMenu(tag, e) {
            const menuMinWidth = 105
            const offsetLeft = this.$el.getBoundingClientRect().left // container margin left
            const offsetWidth = this.$el.offsetWidth // container width
            const maxLeft = offsetWidth - menuMinWidth // left boundary
            const left = e.clientX - offsetLeft + 180 // 15: margin right

            if (left > maxLeft) {
                this.left = maxLeft
            } else {
                this.left = left
            }

            this.top = e.clientY
            this.visible = true
            this.selectedTag = tag
        },
        closeMenu() {
            this.visible = false
        },
        handleScroll() {
            this.closeMenu()
        }
    }
}
</script>

<style lang="scss" scoped>
.tags-view-container {
    height: 34px;
    width: 100%;
    background: #fff;
    border-bottom: 1px solid #d8dce5;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, .12), 0 0 3px 0 rgba(0, 0, 0, .04);

    .tags-view-wrapper {
        .tags-view-item {
            display: inline-block;
            position: relative;
            cursor: pointer;
            height: 26px;
            line-height: 26px;
            border: 1px solid #d8dce5;
            color: #495060;
            background: #fff;
            padding: 0 8px;
            font-size: 12px;
            margin-left: 5px;
            margin-top: 4px;

            &:first-of-type {
                margin-left: 15px;
            }

            &:last-of-type {
                margin-right: 15px;
            }

            &.active {
                background-color: #42b983;
                color: #fff;
                border-color: #42b983;

                &::before {
                    content: '';
                    background: #fff;
                    display: inline-block;
                    width: 8px;
                    height: 8px;
                    border-radius: 50%;
                    position: relative;
                    margin-right: 2px;
                }
            }
        }
    }

    .contextmenu {
        margin: 0;
        background: #fff;
        z-index: 3000;
        position: absolute;
        list-style-type: none;
        padding: 5px 0;
        border-radius: 4px;
        font-size: 12px;
        font-weight: 400;
        color: #333;
        box-shadow: 2px 2px 3px 0 rgba(0, 0, 0, .3);

        li {
            margin: 0;
            padding: 7px 16px;
            cursor: pointer;

            &:hover {
                background: #eee;
            }
        }
    }
}
</style>

<style lang="scss">
//reset element css of el-icon-close
.tags-view-wrapper {
    .tags-view-item {
        .el-icon-close {
            width: 16px;
            height: 16px;
            vertical-align: 2px;
            border-radius: 50%;
            text-align: center;
            transition: all .3s cubic-bezier(.645, .045, .355, 1);
            transform-origin: 100% 50%;

            &:before {
                transform: scale(.6);
                display: inline-block;
                vertical-align: -3px;
            }

            &:hover {
                background-color: #b4bccc;
                color: #fff;
            }
        }
    }
}
</style>
